Jacobs



UNITED STATES PATENT OFFICE.

ARMAND MULLER-JACOBS, on NEW YORK, N. Y., ASSIGNOR TO THE HELIOCAUSTICART COMPANY, or SAME PLACE.

PROCESS OF PRODUCING PHOTOGRAPHS ON HARD SURFACES.

SPECIFICATION forming part of Letters Patent No. 474,850, dated May 17,1892.

Application filed August 23, 1890. Renewed September 12, 1891. SerialNo. 405,566. (No specimens.)

To on whom it may concern-.-

Be it known that I, ARMAND Mi'ILLER- JACOBS, a citizen of the Republicof Switzerland, and a resident of New York, in the county of New Yorkand State of New York, have invented certain new and useful Improvementsin the Process of Producing Photographs, &c.,on Hard Surfaces, of whichthe following is a specification.

My invention has reference to a new process of producing photographs,images, and pictures on hard surfaces, as glass, metal, porcelain, &c.;and the invention consists in applying to such a surface a coating of asolution of guaiaretic acid or of the guaiarefate of a metal or organicbase and submitting the so-coated surface under a photographic negativeor a transparent positive of the image to the action of the light,whereby the parts of the coating exposed to the light through theunaffected parts of the negative or transparent positive become hard andinsoluble, then developing the coated surface,

and finally applying to the film a suitable acid, whereby the picture isetched into the surface. The hard portions of the film which are notaffected by the acid are then removed.

I have found that the guaiaretic acid (O l-1 ,0 or its metallic salts,or those made of guaiaretic acid with organic bases, by ex posure tolight change their properties as to solubility and as to resistance tooxidizing agents. The guaiaretic acid, as well known, is, freshlyprepared, soluble in alcohol, ether, bisulphide of carbon, chloroform,acetic acid, benzole, and other substances; but by exposore to light itbecomes less or entirely insoluble in these substances, like'asphaltumor resinates-that is to say, the salts of abictic acid, (C,,,,H,,,O Asfar as my researches go guaiaconic acid (0,, H 0 is formed by thisaction, which latter is still more oxidized by certain likewise-actingsubstances. A similar effect takes place by exposing the salts ofguaiaretic acid with metals or organic bases, also the chlorine,bromine, and iodine substitution products or the corresponding. salts tothe action of light. Certain colorsfor instance,'anilin-violet,magenta-red, safrauinewhen combined in minute quantities with guaiareticacid or its salts accelerate the action of the lighti. a, they act assensitizers. I furthermore found that a thin coating of thisacid or itssalts laid upon a hard surface and exposed to the light for a certaintime becomes impermeable by dilute universal or organic acids. Theseproperties of guaiaretic acid or its salts, as aforesaid, render themuse ful for the production or reproduction of pictures, photographs,ornaments, &c., by means of the actinic rays.

In carrying out my invention to produce a photograph, picture, image, orornaments on a hard surface, as metal, porcelain, glass, lithographicstone, &c., I first dissolve one hundred parts of crystallizedguaiaretic acid, or, to obtain a more sensitive film, one hundred andtwenty parts of dry amorphous gnaiaretate of silver or of acorresponding quantity of the zinc, lead, or magnesium salt (whichlatter are less sensitive than. the silver salt) in five hundred partsof pure benzole. I may use the salts colored with three to four percent. of aniline-violet or another aniline color or colors. I thenprepare a rubber solution by dissolving seven and one-half parts of drycaou tchouc in five hundred parts of benzole. I may also use a collodionsolution instead of rubber, the collodion solution containing one to twoper cent. of nitro-cellulose; but I prefer the above-describedcomposition of rubber. Both solutions are then thoroughly mixed togetherand the Well-cleaned surface on which the picture is to be produced iscarefully coated with the mixture thus obtained in the dark. Then theso-coated surface is exposed under a negative or transparent positive tothe action of light, aten to twelve minutes exposure to direct sunlightbeing sufficient to harden the exposed parts and to render theminsoluble in the developing-bath, and the best I found to be composed ofa mixture of one part of benzole and five parts of spirits ofturpentine. Of course other developers can be used. The parts of thefilm which are not alfected by the action of the light are therebyremoved and the picture appears on the surface. The plate is then driedand etched by appropriate acids, according to the nature of the surfaceto which the sensitive film is applied; or it may be printed fromdirectly with lithographic ink.

into a tray containing a weak solution of sulphuric, hydrochloric, orany other suitable acid to precipitate the guaiaretic acid in thegelatine film, or in a weak solution of a salt of a metalfor instance,of nitrate of silver, sulphate of magnesium, &c.to form aguaiaretate.The film can be more sensitized if it is brought after thoroughlywashingin avery "dilute bath of an aniline color, as above mentioned.After a second drying the film is exposed and the negative ortransparent positive and developed by means of the benzole developer.The gelatine film is then, after drying, hardened by chromic or commonalum, tannic acid, or any other suitable substance. The surface havingthe thus-prepared picture can afterward be etched with the appropriateacid.

The guaiaretic acid which I use is prepared in the following way: Twoparts of guaiacum are dissolved in ten parts of alcohol, filtered, andconcentrated to a thin sirupy solution, Then it is mixed with a warmconcentrated solution of one part of potassium hydrate. Aftertwenty-four hours standing it forms a mass of the consistency of pulpand is pressed through a filtering-cloth. The remainder is thoroughlyWashed first with alcohol and then with water and crystallized by meansof dilute alcohol. 7 7

Having thus described my invention, I claim as new and desire to secureby Letters Patent 1. The process of producing photographs, images, andpictures on hard surfaces, which consists in coating the surfaces with asolution of guaiaretic acid or of the guaiaretate of a metal or organicbase, subjecting the so-coated surface under a negative ortransparentpositire to the action of the light, andafter developing thesame subjecting the surface to a suitable acid, by which the photographor image is etched into thesurface, substantially as set forth.

2. In the art of photography, the process which consists in coating asurface with a guaiaretic acid or its metal or organic salts as theessential sensitizing medium,substa ntially as set forth.

Signed at New York, in the county of New York and State of New York,this 5th day of August, A. D. 1890.

ARMAND MULLER-JACOBS.

Witnesses:

CHARLES KARP, JOHN J. PoWERs.

